Practical Pyrogallol‐Derived Epoxy Resins via Low‐Temperature Two‐Step Synthesis: Unlocking High Efficiency and Thermal Stability for Sustainable Application

ABSTRACT As the depletion of fossil resources drives the demand for sustainable alternatives, bio‐based epoxy resins (EP) face a critical challenge in balancing processability and mechanical performance. This study presents a novel low‐viscosity EP, c‐E3PG, synthesized from renewable pyrogallol via a two‐step low‐temperature method. By optimizing reaction conditions, c‐E3PG achieves a high yield (65.8%) of the target compound E3PG (pyrogallol triglycidyl ether) with minimal byproducts, exhibiting a viscosity of 1500 cps at 25°C—significantly lower than conventional petroleum‐based resins. Curing kinetics analysis reveals a low activation energy (70 kJ/mol), enabling efficient crosslinking, while the cured resin demonstrates a glass transition temperature ( T g ) of 145°C, storage modulus ( E′ ) of 2900 MPa, and exceptional electrical insulation properties (breakdown strength: 142.41 kV/mm; volume resistivity: 11.0 × 10 15  Ω·cm). These results highlight c‐E3PG's dual advantages of ease of processing and robust thermomechanical performance, positioning it as a scalable, eco‐friendly alternative for high‐temperature packaging and electrical insulation applications.